The pet co I went to was for fish dogs and reptiles mostly. They have a huge fish section. Every tank had a substrate, which in most tropicals, was sand or a dark gravel. The tanks were very clean and the fish were extremely active. To my suprise they actually cared for the fish. It is the worst place to go if you have MTS because they have like 15 empty tanks on the floor for purchase. I wanted to get a 39 bow front complete with lid and stand for $66 but know I would have gotten chewed out for it. My point is that this is the first pet store where the fish are kept nice and in a good environment I have ever seen. The largest and most aggressive fish are kept alone in large tanks. The only problem was that the Betta's were still kept in those small bowls but the water was very clean. I hope for my fish to live long and happy lives and seeing as how they were kept compared to places I used to go, they should.

I just have two simple questions. One is that I saw some black widows there and they were the long finned kind. Are they just natural or altered somehow? Would getting one more black widow female overstock my 10 gallon?

Also, What are a few scientific plant names that would look good in my tank and grow in low light. The plants they have there are in these little tubes and they have this jelly like thing that keeps them alive and allows their roots to grow. (the plant I had said "Tropica Fern" and ther was no L.) Then it has the scientific name under that (in this case Microsorium Pleropus)

The long finned fishes have been bred from the common ones. They have done it in several other species, danios and bristlenoses come to mind. They are natural, just that someone noticed some of their fish had longer than usual fins so bred from them to get the longer finned variety.
I would not be keen to add one to your current stock. I have found that one added to an existing group is often harrassed by the others. I try to add shoaling fish in groups rather than singles and you tank isn't big enough.